The thermal conductivity of "pastas" in neutron star matter

TL;DR

This paper investigates how the thermal conductivity of nuclear matter in neutron stars changes during phase transitions, revealing a dramatic shift around T=1 MeV and decoupling effects in asymmetric matter.

Contribution

It provides the first molecular dynamics simulation analysis of phononic thermal conductivity across topological and phase transitions in neutron star matter.

Findings

Thermal conductivity changes dramatically near T=1 MeV.

Pasta breakdown occurs during heating process.

Decoupling observed in asymmetric nuclear matter.

Abstract

This investigation explores the phononic thermal conductivity of nuclear star matter as it undergoes the "topological" transition to the "pasta" regime, and further down to the solid-liquid phase transition. The study was carried out using molecular dynamics simulations with nuclear potentials embedded in an effective (i.e. Thomas-Fermi) Coulomb potential. The thermal conductivity experiences a dramatic change within a narrow temperature interval around T=1 MeV. This change accomplishes the "pasta" breakdown during a heating process. The thermal conductivity by flipping protons' or neutrons' velocity further shows a decoupling for asymmetric nuclear star matter.